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Technologies - Water Heating and Water Treatment

 

WATER HEATING
In a traditional hot water system, a water heater heats water which then flows from the water heater to each faucet or showerhead in the home or facility. After each application, water remains in the pipes where it cools down. The next time hot water is required, the cool water in the pipes is often allowed to run until hot water becomes available, wasting between 8,000 - 20,000 gallons a year. Systems that provide hot water immediately on demand (or instantaneously) are described below.
Hot Water-Recirculating System
Water Heating and Water Treatment, PhotoIn these systems, water in the hot water line recirculates between the faucet and the water heater so that the water stays hot. This prevents the practice of letting water run down the drain while waiting for heated water. The system consists of a hot water line that loops from the water heater to the farthest fixture and back to the water heater, a pump to recirculate the water, thermostat, isolation valve and check valve. Systems may include a timer that can be set for a specific time of day or a switch to start the water circulating. Significant water savings can be realized, especially, when hot water has to travel a significant distance to the farthest fixture. According to manufacturers' estimates, the average home wastes between 11,000 and 15,000 gallons of water every year as people wait for hot water. Re-circulating systems are sometimes required in new construction. Rebates and discounts may be available for retrofits of existing homes and buildings.
Point of Use Water Heater
A "point of use" water heater is installed directly under the sink or where ever hot water is required and produces hot water instantly.
Point of Use Tankless Water Heater
A tankless water heater can be located at the point of use and provides unlimited instantaneous hot water. It does not have a storage tank, and gas models often do not have standing pilot lights, thereby saving energy.
WATER TREATMENT
Water Softeners

Water softeners remove the "hard" minerals calcium and magnesium from water that lead to soap deposits on bathtub and sinks, dull-looking laundry, spotty dishes, and scaly deposits on fixtures, water heaters and pipes. In a typical softener, the water exchanges its calcium and magnesium "hard" ions for the "soft" sodium ions contained in synthetic resin beads in the softener tank. Once the sodium supply in the resin beads has been exhausted, it is replenished by backwashing a water/salt solution (brine) through the resin beads. This process, called "regeneration", uses between 15 and 120 gallons of water for every per 1,000 gallons softened, depending on the type of unit.

Water Softener Regeneration

 

 

 

 

Water Softener Sustainability

Large facilities often control softener regeneration frequency with timers or water meters which initiate the regeneration process when a predetermined amount of water has been treated. The best systems have controls that monitor water quality and initiate the regeneration process when the softened water becomes slightly hard. At smaller facilities, softeners are serviced by a water treatment company and their components are regenerated off-site at the vendor's facility.

 

 

Want to learn more about water softeners, salinity issues and solutions, as well as where to find water professionals who are certified on water softener sustainability? Check out the Arizona Water Quality Association's website: http://wsspa.org/

Water Purification
There are several ways to purify water. Two common methods are reverse osmosis and filtering. In reverse osmosis (RO), water is forced through an ultra fine membrane which separates clean water from the brine. RO removes nitrates, sulfate, sodium and total dissolved solids. Household RO units recover only 5 to 15 percent of the water entering the system, due to low back pressure. In other words, to make 5 gallons of purified water, 40 to 90 gallons of water are discarded. Filtering water is usually accomplished with charcoal filters installed in faucets, icemakers, and other fixtures. Charcoal has a large porous surface area that absorbs sediments and impurities such as gases, chlorine and organic contaminants that have undesirable flavors or odors. Activated charcoal has been heat-treated to increase the pores and therefore the surface area. Charcoal filters do not remove nitrates, bacteria or dissolved minerals or salts. For water that is high in contaminants, a unit that combines reverse osmosis and charcoal filtration could be beneficial
Water Purification Water quality monitoring kits
Water monitoring test kits are usually used by homeowners with wells or when water contamination is suspected due to undesirable taste, odor and/or color. The easy-to-use kits test water for total coliform bacteria, nitrates, total dissolved solids and pH levels.